In a data center, server racks are typically provided with power via a plurality of rack receptacles. The receptacles are electrically coupled via one or more whips to a power distribution unit (PDU), which can include a variety of power processing components. The PDU usually receives power from both a primary external power source, and a secondary utility source fed by an alternate distribution—such as a public utility line into the building. However, during a power event/loss on the primary utility source, an automatic transfer switch (ATS) can change the source of power for the PDU to the secondary power source to ensure the electrical equipment remains powered at all times. Both of the incoming primary and secondary utility sources to the PDU may have full redundancy and include an upstream switch which can be fed by either the incoming utility source or a generator, and may further include batteries to back up the power supply during that transition so that there is never an interruption to the power going into the PDU.